Member postings for Bill Davies 2

A step chuck, a kind of collet. Two kinds, this is the concave version for holding outside diameters.

https://www.youtube.com/watch?v=UtBtaFUyo6Y

Bill

I have a similar bench drill I bought some years back, similar to offerings from B&Q and Wickes. I've never noticed it running hot, but has about similar power to my similarly powered pistol drills (B&D, Bosch).

The table is a bit flimsy (someone recently suggested a scissor jack underneath, I've used blocks of wood). In steel, you have to progressively take the drill sizes up to the final size required, or it stalls. It does the job, but probably maxes out at about 1/2 inch or so diameter. Mine cost £40, back then.

Bill

No disagreement with Mark, but the 20° pressure angle was common when I started my apprenticeship in 1968. The 14-1/2° is to match the older machines that many of us have. Just a comment to reinforce the need to check.

Bill

Yes, it annoys me... Blame the lawyers - no, really, they seem to have changed the meaning from a collection of people coming to a common agreement to something not worthy of discussion.

Larry, I would guess that the feed per tooth in wood is hugely more than in metals, so a small eccentricity is noticeable in slitting saws. Plus, in my experience, horizontal mill arbours (where I have used slitting saws) are always bent to some degree.

Bill

Hi, Adam.

Assuming the cross slide, the dial movement indicates the amount removed on the diameter. Half off radius (actual slide movement) equals amount off diameter.

Bill

Sorry, that should be power resistors.

Not the most efficient way, dump some of the heat in a rheostat:

**LINK**

Cheaper would be a string of powers such as:

**LINK**

I don't think your large power supply will like chopped AC going into it, whether an old-school transformer type (is it heavy?) or a modern switched-mode type. The latter type will also regulate itself so the reduced input voltage won't result in a lower voltage output.

Do you know what current is actually being drawn in trying to make your resistance weld? Would it be possible to control the duration of the pulse of electricity to control the amount of energy delivered?

Bill

The bore gauge looks nice, Duncan. Here is a Mitutoyo version:

**LINK**

Just don't look at the price!

Bill

And I can't be the only person searching for his glasses, only to discover I'm wearing them...

Hi, Sam. Involute gears roll where their pitch circles touch; they slide above and below this point. Lubrication avoids (continued) metal to metal contact, it allows sliding between parts, once an oil film has formed, as in plain bearings.

In the case of pick-off (or change) gears for screwcutting, etc., some oil makes the gears a little quieter.

In higher speed gears, as in closed gear boxes, the oil also helps to remove heat caused by friction.

Bill

XD351 - 10c tax, redeemable. When I was a lad in the Sixties, we would round up soft drink bottles for the cash back, as a supplement to our pocket money. I think any off-licence would pay you in exchange for the empty. Some older lads at my school found a better way, they nicked R Whites lemonade bottles from the nearby distribution centre, drank them and got paid for it.

Bill

A couple of more images from the book, showing the grinding of the die rake angles.

Bill

I have a pdf of The Book of the Coventry Diehead (25th Ed). It mentions UNC and UNF, so is post-1949, perhaps late-50s to 1960s. I don't know where I downloaded it, so can't post a link.

It mentions several jig types, including one for 12 degrees rake angle. It also mentions M-type dies are ground parallel to their back. I enclose a couple of pics from the book for a type which allows different rake angles.

It shows the clamps on the left for grinding top rake, and on the right for grinding the 'throat' or lead-in of the die.

My recollection from long ago (unreliable) is that the die rake angle was zero degrees, and that there was a simple jig, perhaps shop-made, not a branded one, for use on a cutter grinder or surface grinder.

Larger copies are my album.

Bill

My experience is like Bazyle's. Looking to buy a few common resistors or transistors, only two in stock. And yet they do seem to stock some less common items. There were three stores in Cardiff, now two. They shut the better one, from a technical knowledge point of view. Not having stock, they would refer me to buy online, 'but I want in now, or I wouldn't be here.'

Similarly, I use Homebase, not the cheapest but convenient. Bunnings (Australian DIY) took them over, and now they seem to be in trouble. I was told a few weeks ago that they were doing more DIY. Like B&Q, Screwfix (yes I know), Wickes, etc., I said. No competition there, then.

Bill

Neil, I had a similar experience, I think in 1991. In student accommodation at Aberystwyth Uni, I felt what I thought was a large lorry pass by - I was in a corner room on the top floor. I realised there was no road running by the hall, and wondered what it was. The news that evening reported the earthquake. The student in the next room felt nothing. I think it was the quake at Bishop's Castle that year.

Bill

I'm in Cardiff, but didn't notice anything. My son in law, elsewhere in Cardiff, did, so the effects seem to be a bit localised.

Bill

Is the "gubbins" a mechanism for opening/closing collet jaws?

Bill

Out of hibernation?

Bill

+1 for Internal Fire. I've visited several times, very enthusiastic team of volunteers. Large stationary internal combustion engines, several running each time I visited, and a willingness to start up any of interest (I suppose if they are not too big). Last time I went, they had a steam engine they intended to get running.

Also, some mid-century radio and telecoms equipment. I also had a quick view of their workshop; about as tidy as mine, but producing somewhat larger work.

I moved from Surrey to Somerset, then Wales. It definitely gets wetter as you go west! Bore da, all.

Bill